package pers.sports.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Random;

@Controller
public class CheckcodeController {

    private static final int w = 75; //验证码图片宽度
    private static final int h = 35; //验证码图片高度

    private final Random r = new Random();
    private final String[] fontNames =
            {"宋体", "华文楷体", "黑体", "微软雅黑", "楷体_GB2312"};
    // 可选字符
    private final String codes = "23456789abcdefghjkmnpqrstuvwxyz";
    // 背景色
    private final Color bgColor = new Color(255, 255, 255);
    // 验证码上的文本
    private String text;

    @RequestMapping("/checkcode")
    public void checkcode(HttpServletRequest request, HttpServletResponse response) throws IOException {
        HttpSession session = request.getSession();
        response.setContentType("image/jpeg");
        ServletOutputStream sos = response.getOutputStream();
        //设置浏览器不要缓存此图片
        response.setHeader("Pragma", "No-cache");
        response.setHeader("Cache-Control", "no-cache");
        response.setDateHeader("Expires", 0);
        //创建内存图象并获得其图形上下文
        BufferedImage image = createImage();// 创建图片缓冲区
        Graphics2D g2 = (Graphics2D) image.getGraphics();// 得到绘制环境
        StringBuilder sb = new StringBuilder();// 用来装载生成的验证码文本
        // 向图片中画4个字符
        for (int i = 0; i < 4; i++) {// 循环四次，每次生成一个字符
            String s = randomChar() + "";// 随机生成一个字母
            sb.append(s); // 把字母添加到sb中
            float x = i * 1.0F * w / 4; // 设置当前字符的x轴坐标
            g2.setFont(randomFont()); // 设置随机字体
            g2.setColor(randomColor()); // 设置随机颜色
            g2.drawString(s, x, h - 5); // 画图
        }
        this.text = sb.toString(); // 把生成的字符串赋给了this.text
        drawLine(image); // 添加干扰线
        //将图像输出到客户端
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        ImageIO.write(image, "JPEG", bos);
        byte[] buf = bos.toByteArray();
        response.setContentLength(buf.length);
        //下面的语句也可写成：bos.writeTo(sos);
        sos.write(buf);
        bos.close();
        sos.close();
        //将当前验证码存入到Session中
        session.setAttribute("checkcode", new String(text));
        //直接使用下面的代码将有问题，Session对象必须在提交响应前获得
    }

    // 生成随机的颜色
    private Color randomColor() {
        int red = r.nextInt(150);
        int green = r.nextInt(150);
        int blue = r.nextInt(150);
        return new Color(red, green, blue);
    }

    // 生成随机的字体
    private Font randomFont() {
        int index = r.nextInt(fontNames.length);
        String fontName = fontNames[index];// 生成随机的字体名称
        int style = r.nextInt(4);// 生成随机的样式, 0(无样式), 1(粗体), 2(斜体), 3(粗体+斜体)
        int size = r.nextInt(5) + 24; // 生成随机字号, 24 ~ 28
        return new Font(fontName, style, size);
    }

    // 画干扰线
    private void drawLine(BufferedImage image) {
        int num = 3;// 一共画3条
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        for (int i = 0; i < num; i++) {// 生成两个点的坐标，即4个值
            int x1 = r.nextInt(w);
            int y1 = r.nextInt(h);
            int x2 = r.nextInt(w);
            int y2 = r.nextInt(h);
            g2.setStroke(new BasicStroke(1.5F));
            g2.setColor(Color.BLUE); // 干扰线是蓝色
            g2.drawLine(x1, y1, x2, y2);// 画线
        }
    }

    // 随机生成一个字符
    private char randomChar() {
        int index = r.nextInt(codes.length());
        return codes.charAt(index);
    }

    // 创建BufferedImage
    private BufferedImage createImage() {
        BufferedImage image = new BufferedImage(w, h,
                BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        g2.setColor(this.bgColor);
        g2.fillRect(0, 0, w, h);
        return image;
    }

    @ResponseBody
    @RequestMapping("/checkcodetext")
    public String checkcodetext(HttpServletRequest request) {
        String checkcodetext = request.getSession().getAttribute("checkcode").toString();
        return checkcodetext;
    }

}
